4.5.1.1 Quantities

Spec reference: 4.5.1 (subtopic).

What you need to know

• Quantities
• A scalar quantity has magnitude only. Examples include temperature or mass.
• A vector quantity has both magnitude and direction. Examples include velocity.
• Speed is the scalar magnitude of velocity.
• A vector quantity can be shown using an arrow. The size of the arrow is relative to
• the magnitude of the quantity and the direction shows the associated direction.
• Gravity
• Gravity is the natural phenomenon by which any object with mass or energy is drawn together.

Self-assessment (checklist)

• I can explain the difference between scalar and vector
• I can describe how to represent a vector quantity.

Key steps (method)

• Identify what the question is testing and use the correct equation/definition.
• Show substitutions and units clearly.

Common mistakes

• Unit conversions, rearranging errors, or quoting a law without applying it.